1. The Field of the Invention
The present invention relates generally to mechanisms for recovering from a failure in a computing or electronic system using watchdog signals. More particularly, the present invention relates to the generation of watchdog signals using watchdog instructions embedded in microcode that is executed by a processor.
2. Background and Relevant Art
Electronic and computing technology has transformed the way that we work and play. The complexity of such systems facilitates the accomplishment of complex tasks that would not be possible (or at least would be very difficult) without the assistance of the system. While this complexity provides great utility to the user, the complexity can also result in problems.
A common problem is for a system to cease or slow operation due to some encountered instability. For example, two modules or programs may encounter a conflict, or perhaps memory management trouble occurs. In systems in which operational continuity is important, the system is configured to periodically generate watchdog signals which are propagated throughout the system. If the system does not periodically generate the watchdog signal, then the system has likely ceased operation or at least has diminished operation. In that case, the system performs some other operation tending to correct the encountered instability. A typical corrective operation would be to restart the system with a clean state, or reset one or more components of the system.
Occasionally, the system may fail such that watchdog signals are not propagated when there is no instability, thereby causing inappropriate corrective action such as a reboot or reset of a properly running system. Alternatively, the system may improperly propagate watchdog signals when there is an instability warranting corrective action, thereby guaranteeing that correction action is not taken.
Accordingly, what would be advantageous is a mechanism in which watchdog signals are made a more reliable indicator of whether or not the system is experiencing an instability warranting corrective action.